U.S. Pat. No. 2,036,560 issued Apr. 7, 1936 to W. T. Backus for "Land Vehicle Equipment" documents an early attempt to improve the streamlining of moving vehicles by reducing the airflow under the vehicle. The patentee pointed out that the undersurface of a vehicle "is the source of even more loss of efficiency than results from unimproved upper surfaces of the same vehicle" for two reasons. "First, numerous projections on the bottoms of vehicles increase the amount of wind resistance; and, second, the air pressure which is built up underneath the moving car in the restricted space between the bottom surface of the vehicle and the ground increase the amount of drag or retardation from wind resistance." The patentee's solution was to provide a hydraulically adjustable airfoil at the front of the vehicle that had a non-convex upper surface to direct air up and over the vehicle.
Subsequently, it was determined that an airfoil or a spoiler mounted beneath the front end of the vehicle also would be advantageous to reduce drag. The January 1970 issue of Motor Trend Magazine, at page 40, shows a vehicle having a fixed spoiler mounted beneath the streamlined nose of the vehicle. The caption accompanying the picture states, "Spoiler not only kills front end lift, but lowers overall drag by limiting airflow under the car and also aids engine cooling." Such fixed spoilers have been used on many racing cars and high powered sport model versions of passenger cars.
U.S. Pat. No. 3,618,998 issued Nov. 9, 1971 to D. A. Swauger for "Wind Load Applicator and Stabilizer for Steerable Front Wheels of Rear-Engine Vehicles" carried the concept of a front end stabilizer or spoiler mounted beneath the vehicle a step further. The Swauger patent discloses an airfoil member pivotally mounted adjacent and relative to a flat pan bottom of a well known type of vehicle. A spring-loaded means supports the airfoil member in a normally raised position. The spring-loaded means is yieldable, however, under increased air pressure as the vehicle velocity increases, to permit increased downward inclination of the airfoil and, therefore, greater downward pressure of the tires of the vehicle upon the pavement.
It is an object of the present invention to provide a spoiler that is self-deployable in response to increased speed of the vehicle. The spoiler is substantially concealed beneath the front end structure of the vehicle at no or low speed, but is adapted to self-deploy when the vehicle reaches a critical speed at which such a device becomes effective or beneficial.